The present invention relates to connectors for electrodes. More particularly, it relates to an electrode clip for the connection of a lead cable to a monitoring electrode which, in turn, is secured to a patient.
The physiological functioning of the human or animal body results in certain electrical phenomena. Such phenomena are monitored, for example, by electrocardiographic instrumentation. The instrumentation is typically connected to the body by a lead cable, a connector and an electrode. The lead cables are connected to the instrumentation. The electrodes are applied to the skin. The cables and electrodes are typically interconnected by the connectors.
The electrodes may be connected to the skin by a suction cup, aided by an electrically conductive gel or cream, or they may be glued or taped to the patient's body. The electrode is typically provided with a male pin or male snap fastener. The female portion of the snap is fastened to the connector and is intended to mechanically couple with the male portion. Several different types of cable fasteners are used to couple electrical impulses from the electrode on the patient's body to a cable connected to an electrocardiograph or other monitoring device. The object of all such monitoring electrodes and related connectors is to insure a good electrical and mechanical connection between the skin of the patient and the lead cable.
For example, U.S. Pat. No. 3,740,703 discloses what is referred to as a terminal clip for connecting a lead conductor to an electrode for making electrical connection to skin. The electrode includes what is referred to as a button type male terminal. The clip includes a spring and is constructed to engage the terminal by relative lateral movement of portions of the clip transverse to the axis of the button terminal. Another spring connector is disclosed in U.S. Pat. No. 3,829,826. There, a male snap fastener is held in contact with the cable fastener by a spring. The fastener is said to be small enough to allow shielding of the cable right up to the skin.
U.S. Pat. No. 3,976,055 discloses another electrode for sensing electrocardiograph signals. In FIG. 3, the central conductor has been press fitted into a conventional snap fastener. In FIG. 2, two central conductors are shown connected to an impedance meter by a pair of "alligator" clips.
U.S. Pat. No. 4,303,293 discloses another electrode clip. The clip is formed of resilient plastic material such as polypropylene. Through a series of jaws and living hinges, the electrode clip is secured to what is referred to as an electrode stud on an electrode. The electrode stud, as shown and described, is a traditional male pin or male snap fastener. Hence, the patient is drawn to another type of male and female connector.
The prior devices have concentrated on mechanically adapting both the electrode and the connector to provide a good electrical connection there between. This has been done for two major reasons. First, the strength of the mechanical connection is tested every time the patient moves. Second, the electrical phenomena being monitored is relatively faint. The electrical connection must be quite good to satisfactorily transmit the electrical phenomena to the lead cable and to the monitoring instrumentation.
Where the connector alone has been concentrated on for providing an adequate mechanical and electrical connection between the electrode and the lead cable, the resultant connector has included various clamps, jaws and levers. For example, the connector disclosed in U.S. Pat. No. 4,061,408 includes a pivotally mounted lever for opening and closing the connector.